Means for unloading steel sheets from carrier sheets



Dec. 29, 1931. R. s. COCHRAN ET AL MEANS FOR UNLOADING STEEL SHEETS FROM CARRIER SHEETS Filed May 15, 1950 gyvvz'ntow R.5.Coch1"an A.L Larsen,

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Patented Dec. 29, 1931 UNITED STATES PATENT OFFICE RALF S. COCHRAN AND ARNOLD L. LARSEN, OF TOLEDO, OHIO, ASSIGNORS TO SURFACE COMBUSTION CORPORATION, OF TOLEDO, OHIO, A CORPORATION OF NEW YORK MEANS FOR UNLOADING STEEL SHEETS FROM CARRIER SHEETS Application filed May 15, 1930. Serial No. 452,738.

This invention relates to the handling of steel sheets as they are discharged from a continuous heat treating furnace wherein the sheets are subjected to heat treatment as for annealing or normalizing.

In order to prevent marring of the surface of the steel sheet by the conveying mechanism and more particularly where such conveying mechanism comprises a bed of power-driven 1o discs, the practice is to support the sheets on carrier sheets known in the art as wasters. After the steel sheets supported as said leave the furnace, it is necessary to separate the steel sheets from the carrier or waster sheets.

With the above facts in mind, it is an object of the present invention to provide ways and means for automatically separating the steel sheets from the carrier sheets after said sheets leave the furnace.

In accordance with this invention, the carrier sheet is made of non-magnetic material such as austenitic steel, preferably a chromenickel steel. The sheet steel, hereinafter also termed work, to be heat treated is placed 25 on the carrier sheets before being entered into the furnace and then moved through the furnace while so supported. The work after having passed through the furnace is unloaded from the carrier sheets by means comprising a belt, the lower lap or run of which is disposed above the path of travel above the work, there being disposed immediately adjacent the upper surface of the lower lap of said belt a magnet or a series of magnets through the magnetic field of which the belt is movable. As the work passes beneath the belt, the magnet causes the work to rise into contact with the belt and to remain in contact therewith for movement thereby while the work passes through the magnetic field. The carrier sheet being non-magnetic is not lifted by the magnet and may therefore be disposed of while the work is elevated therefrom.

The invention will be more particularly described in connection with the accompanying drawings in which,

Figure 1 is a vertical longitudinal section through the discharge end of the furnace and the handling mechanism used in conjunction therewith.

Figure 2 is a side elevation on an enlarged scale of the device for separating the work from the waster sheets, some of the mechanical elements being shown diagrammatically.

Figure 3 is a sectional view on an enlarged scale taken on the line 3-3 of Figure 1.

Figure 4 is a plan view of the mechanism for removing the waster sheets and advancing the work.

Figure 5 is a detail view of one form of gearing which may be used in connection with the discharge of the waster sheets.

In the drawings, numeral 6 indicates the discharge end of any suitable heat-treating furnace, the same being shown as provided with a bed type of conveyor B comprising a plurality of discs 7 affixed to transversely extending shafts 8 which are driven in unison by any suitable mechanism conventionally illustrated as a chain and sprocket drive 9, the bed extending some distance beyond the exit end of the furnace.

The carrier sheets are identified by reference character C and the steel sheet to be heat-treated by W.

Sheet steel as produced in steel millsvaries in length from 6 ft. to 12 ft. and is about 3 ft. wide and for heat treatment is passed lengthwise through the furnace. In order to increase the capacity of a sheet heating furnace, it is made wide enough to accommodate a. plurality of sheets, the width usually being such as to accommodate three sheets side by side, the furnace therefore usually being in excess of 9 ft. wide. The carrier sheets instead of being arranged lengthwise of the furnace are arranged crosswise thereof and are of suflicient length transversely of the furnace to support all of the steel sheets W that may be arranged side by side within the furnace.

Above the bed of the conveyor B at its discharge end is arranged an endless belt 10 9 which is looped over driving rollers 11, supported by a suitable frame work 12, the belt being so positioned that its lower lap 10' is in spaced relation with the plane of the conveyor bed B in order that the work W sup- 1.

ported on the carrier sheets C may be free to move beneath the belt.

Between the upper and lower laps of said belt 10 is positioned one or more magnets 13 provided with a shoe 14 against which the lower lap of the belt may slide. The belt, 'it may be noted, is a metallic belt and is preferably made of non-magnetic material. The magnets are supported in any suitable manner as by longitudinally extending overhead beams 15 suitably supported on the frame work 12.

As shown on Figure 3, there will preferably be provided as many belts in laterally spaced relation as the number of sheets which can be accommodated in side by side relation within the furnace.

The magnets are preferably electro-magnets adapted to be continuously energized by any suitable means not shown and are of sufficient capacity to lift the work W from the carrier sheets C when the work comes into the magnetic field, the work upon being lifted coming in contact with the underside of the lower lap 10' of said belt for movement therewith, the belt being driven by the rolls 11, in such a manner that the linear speed of the belt shall be the same as that of the work on the conveyor B.

The work W being lifted as said, the carrier sheet C may obviously be removed from beneath the work and the work thereafter being handled in any preferred manner. According to the preferred form of the invention, the work W while being held against the belt by the magnets as said, is carried across a space given over to mechanism for disposing of the carrier sheets and is thereafter deposited on a roller bed S, the receiving end of which is in sufficiently close proximity to the magnetic field to insure that the leading end of the work \V shall be received on said bed in due time after leaving said field, the work after being deposited on said bed being disposed of in any suitable manner but preferably in the manner more fully hereinafter described.

For removing the carrier sheets from below. the work while the latter is lifted by the magnets, there is provided a pair of oppositely positioned shelves 20 and 21 aflixed to individual shafts 22 and 23 respectively. Said shelves are shown as of a width substantially equal to the width of the carrier sheets and as affixed to their shafts by a plurality of finger elements 24. Said shafts 22 and 23 are connected by suitable mechanism for simultaneous turning movement in opposite directions. M

The mechanism for actuating said shafts 22 and 23 is shown as comprising a Worm Wheel 25 on one terminal of each of said shafts, a worm 26 for each worm wheel, said worms being affixed to a shaft 27 having a gear 28 at one end for engagement with 11 rack 29 having two parallel rack arms 30 and 31 between which is a segmental gear 32 afiixed to the shaft of a motor 33, the rack and gear arrangement being such that rotary motion of the motor is converted into reciprocatory motion as will be readily understood, the motor being' under the control of a time limit switch 34 which in turn is controlled by a trip switch 35 carried by the shelf 21, the trip switch being actuated by a carrier sheet when the latter reaches the switch, whereby the shelves 20 and 21 will swing downwardly as said and then back to position.

Mounted for rotation of the shaft 22 are rolls 37 and adjacent thereto are rollers 38 affixed to a shaft 38', the latter being driven by a chain and sprocket gearing 39 from the shaft 8, the rollers 37 being driven by a chain and sprocket gearing 39 from the shaft 38. Shaft 23 may also be provided with rollers 40 and adjacent thereto may also be provided power driven rollers 41 to facilitate passage of the work W onto the roller bed S which latter will ordinarily be driven as by sprocket chains 42, the rollers 40 also being driven by a chain and sprocket 40.

Any suitable mechanism may be employed for removing the sheets W from the rollers S. In the construction illustrated in Figure 1, the sheets W pass between pinch rolls 43 and their front edges are gripped by spring held jaws 44 pivotally mounted on a carriage 45 which is adapted to travel on a track 46. As soon as a sheet is gripped by the jaws 44, the carriage 45 is advanced by lazy-tongs 47 which are retracted through the medium of links 48 connected with a movable carriage 49 which is adapted to be advanced by means of suitable mechanism 19. The jaws 44 are provided with a release arm 50 which strikes an abutment 51 allowing the sheet to drop upon a truck 52.

The mode of operation will be readily understood from the foregoing description but may be briefly described as follows: The carrier sheets C must first of all be of non-magnetic or diamagnetic material. The steel sheets W being placed on the carrier sheets are passed through the furnace for the desired heat treatment. The steel sheets W on emerging from the furnace will be sufficientl v cool to be magnetic. On passing beneath the movable belt, the magnets will lift the steel sheets W into engagement with the beltand thereby .permit removal of the carrier sheet C. The steel sheets W are moved by the belt onto the roller bed S. The carrier sheets pass one at a time onto the shelves 20 and 21 from which they are released upon actuation of the trip switch 35 which controls the motor 33 through the time limit switch 34. The sheets W after bei delivered on the roller bed S may be han ed in any suitable manner as by the means which piles them on the truck 52.

From the foregoing description, it will be seen that there is provided a practical and improved means for handling articles of paramagnetic material and for separating the same from carrier or waster sheets by which they are supported. While the method and mechanism are described in connection with the heat treatment of the steel sheets, it is not necessarily limited thereto. It is also obvious that the conveyor mechanism as well as the other handling mechanism described may be greatly modified without any material departure from the scope of the invention as claimed.

What is claimed is:

1. The combination with a conveyor adapted to convey flat paramagnetic material from a furnace, said conveyor including a sheet of other than paramagnetic material on which the paramagnetic material may be supported to prevent marring, of a table in spaced relation to the discharge end of said conveyor for receiving the supporting sheets, a belt having its lower lap above the level of said conveyor and table and of a length to extend from the one to the other, a magnet above the lower lap of the belt, said magnet being adapted to lift the paramagnetic material from the supporting sheet and hold it in contact with the underside of the belt, whereby the belt may move the paramagnetic material across the unbridged space between the conveyor and table and deposit it on said table.

magnetic material comprislng a conveyor, waster sheets of other material for supporting saidparamagnetic sheets out of contact with the conveyor, a magnet having a field through which the paramagnetic sheets are passed by the conveyor, said magnet being of sufficient capacity to remove the paramagnetic sheets from contact with the waster sheets as they pass through said field, and

means for deflecting the waster sheets from the course of the paramagnetic sheets while they are passing through said field.

3. A device for handling sheets of paramagnetic material, comprising a conveyor, waster sheets of other material for support ing said paramagnetic sheets out of contact with the conveyor, a magnet beneath which the paramagnetic sheets and waster sheets are passed by the conveyor, said magnet having suflicient capacity to lift the paramagnetic. sheets, and means for lowering the waster sheets without tilting them after they are free from the sheets which they support.

4. The combination with a furnace provided with a conveyor for moving through the furnace sheet steel supported on waster sheets of less magnetic properties than the sheet steel, the conveyor extending beyond 2. A device for handling sheets of parathe discharge end of the furnace, of means for removing the sheet steel from the waster sheets, said means comprising a magnet disposed above the discharge end of the conveyor and adapted to lift the sheet steel from the waster sheets, and means for removing the waster sheets while the latter is supported by the magnet.

5. The combination with a furnace provided with a conveyor for moving through the furnace sheet steel supported on waster sheets of less magnetic properties than the sheet steel, the conveyor extending beyond the discharge end of the furnace, of meansfor removing the sheet steel from the waster sheets, said means comprising a magnet disposed above the discharge end of the conveyor and adapted to lift the sheet steel from the waster sheets, means for conveying the sheet steel while supported by the magnet, and means for removing the waste-r sheets from below the sheet steel while the latter is supported by the magnet.

In testimony whereof we aflix our signatures.

RALF S. COCHRAN. ARNOLD L. LARSEN.

from below the sheet steel 

